1. Field of the Invention
The present invention relates to a contact device for electrically connecting a printed circuit board with a flat panel which itself may be in the form of another printed circuit board or, in the preferred configuration, in the form of a liquid crystal display (LCD), through a, connector module of approximately U-shaped cross-section holding the edge of the panel between the legs of the U. The panel has a plurality of contact pads on its edge, and the inside of the first leg of the connector module has a corresponding array of contact elements which connect with the contact pads on the panel when the latter is inserted and which, on the outside of the second leg, connect to corresponding contact traces on the surface of the printed circuit board.
2. Description of the Related Art
In known contact devices of this kind, which are used particularly in handheld cellular telephones with LCD displays, it is necessary to interpose a so-called zebra connector between the contact elements extending on the outside of the second leg and the surface portion of the printed circuit board where the contact traces are located. A zebra connector is a block consisting of sandwiched alternating layers of conducting and non-conducting elastomeric material. Through the conducting layers of the zebra block, a satisfactory connection of the contact elements of the connector module with the contact traces on the printed circuit board is achieved even in case that the LCD panel and the printed circuit board should be joined in a slightly misaligned condition. In particular, the elastically pliable zebra block provides a reliable contact even in case that the plane of the LCD panel in its inserted position should not be absolutely parallel to the printed circuit board but rather enclosing a small angle of a few degrees with the latter.
Particularly under confined spatial conditions inside the enclosure of handheld cellular telephones, the height of this contact device has proven to be a great disadvantage. In addition, there is the required costly expenditure due to the necessity of interposing the elastic zebra connector block.